Polyacrylic acid esters (polyacrylates) are compounds with numerous uses. For polyacrylates from homopolymers the possible uses are rather limited, whereas in the case of polyacrylates from copolymers it is possible, by selecting the comonomers to be used (for example methylacrylates, styrene, acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride and butadiene) to exert an influence on the properties of the polyacrylates in various ways and therefore provide access to the most varied possible uses.
Chemical methods for cleavage of polyacrylic acid esters, for example alkaline saponification (U.S. Pat. No. 3,926,891), are known by a person skilled in the art. US patent application 2004/0082023 A1 describes a method of enzymatic esterification of polymers bearing carboxyl groups using enzymes such as lipases or esterases. Polyacrylates are not named explicitly as possible polymers, nor is there any mention of the suitability of the method for the enzyme-catalyzed ester cleavage of polyacrylate esters.
O'Sullivan and Birkinshaw described an attempt to hydrolyze poly-(n-butylcyanoacrylate) nanoparticles by esterase from pig's liver (O'Sullivan, Birkinshaw, Polymer Degradation and Stability 78: 7-15, 2002). Belucci et al. reported on the careful removal of acrylic resin coatings from the surface of paintings using lipase (Belluci et al., Study in Conservation 44: 278-281, 1999).
A large number of esterases are known by a person skilled in the art. Esterases of Burkholderia gladioli are described for example in Peterson et al., J. Biotechnol. 89:11-25 (2001), Valinger et al., J. Biotechnol. 129:98-108 (2007), Ivancic et al., J. Biotechnol. 129:109-122 (2007) and Reiter et al., Appl. Microbiol. Biotechnol. 54:778-785 (2000). Suitability of these esterases for the cleavage of polymer substrates has not been described before.
The problem on which the present invention is based therefore consists of providing a method for the enzyme-catalyzed hydrolysis of polyacrylic acid esters and suitable enzymes therefor, their nucleic acids, the nucleic acid-containing vectors or the vector-containing microorganisms, and reaction products obtainable by the method.